Upgrade Fuel Pump

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-==L=a=N=c=E==-

New member
While the tank is out ive decided to get a 2nd hand SupraTT pump. They are a direct bolt in as far as im told.

Now after the upgrade, i know my mixtures will run very rich. I have an FCon which im hoping can trim up the fuelling for me, else will i have to get a FPR?

Cheers guys.
 
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illGT4

New member
Get a descent FPR and set it where you want it.

I'm not familiar with the FCon. not sure how much you can adj. Maybe enough though. But, I'd grab a adj. FPR just to have.

Any access to a wideband?
 
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ChrisD

New member
This is a difficult mod. The mr2 board has recently discovered that the stock fuel rail will not flow sufficiently to work with an upgraded fuel pump. There turns out to be a severe pressure drop in the rail. At the FPR side, you would see the pressure that the FPR is set to. At the inlet side, you would see a pressure much higher, and much richer. If you lean out this average of mixtures, you would end up running lean on the cylinders closer to the FPR. (#3, #4).

Tough call. Best move is to run very rich all the time, or upgrade the fuel rail at the same time.
 
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etantshi

Moderator
That shouldn't cause you to run lean on stock injecotrs. If you higher than normal pressure on inlet and regluated pressure closer towards the FPR... then at the very least you'll get normal pressure on 1 and 2. So unless you're counting on higher pressure across the board as a part of your fuel/air calculations, I don't see this as a major issue.
 
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ChrisD

New member
Well, he was talking about using something to lean out the mixture after installing the fuel pump. So if you set a target A/F, say 11.5:1...you will be richer than that on two cylinders and leaner than that on the other two.

So if you are just calculating on being overly rich, and did the calculations, you could easily do it so that all four cylinders are safe.

But yeah, lots of people run bigger pumps without problems. They are probably just running richer than is optimal.

:)
 
L

-==L=a=N=c=E==-

New member
Thanks for the response guys. Im investigating a FPR just in case. And as for the fuel rail, ill see if i can chase up a better flowing one.
 
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ChrisD

New member
Playing with the AFM is sort of a witchcraft if you ask me...I wouldn't like playing with it. If I were you, I'd just get the fuel pump and an adjustable FPR. Then adjust the FPR so that you are a little extra rich to be safe. You can still use the stock rail just fine if you ensure that you are extra rich...lots of people in the past have gotten away without compensating...

For fuel rails, there is a group buy on the mr2 board for the www.wolfkatz.com rail.
 
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Savage

New member
Anyone know what kind of pressure the standard fuel rail will support? What pressure / gph the standard JDM 3SGTE fuel pump puts out?

Cheers
 
L

-==L=a=N=c=E==-

New member
Just a few thoughts.

My fuelling is currently being power off an aftermarket power line, as my stock line is buggered (intermittent break) The pump was running at full speed and i didn't have any ill affects.

NOW, my thoughts are, if there is too much pressure in the lines, what from stopping me from running the pump at a lower voltage (instead of 13.2V) by putting resistors inline with the pump. I personally reckon that would work.

You'd need a way to check the fuel pressure, but apart from that. It is simple, and quite affective (keep in mind the stock pump, on the stock power line runs at half speed when off boost)

What ya reckon?


As for the fuel rail, i remember somewhere about a guy who modified the stock fuel rail, having 2 fuel inlets on either side of the rail, and the FPR in the middle. Would stop the problem of the pressure differential?
 
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tweekgt4

Member
if you modify the stock rail to be a dual feed, you don't have to worry about the pressure drop.

i have also heard that the stock fuel pressure regulator is not very consistent so it should be on the list of things to change out when doing a fuel upgrade.

my current setup now is a supra tt fuel pump, stock dual feed fuel rail, SX rising rate fpr, and st205 540cc injectors at a base pressure of 50 psi.
 
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illGT4

New member
tweekgt4":1spoh5bo said:
if you modify the stock rail to be a dual feed, you don't have to worry about the pressure drop.

i have also heard that the stock fuel pressure regulator is not very consistent so it should be on the list of things to change out when doing a fuel upgrade.

my current setup now is a supra tt fuel pump, stock dual feed fuel rail, SX rising rate fpr, and st205 540cc injectors at a base pressure of 50 psi.
Click to expand...

What boost pressure are you running? Rather what have you got it tuned to?
 
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enzytebob

New member
-==L=a=N=c=E==-":vztntu9y said:
While the tank is out ive decided to get a 2nd hand SupraTT pump. They are a direct bolt in as far as im told.

Now after the upgrade, i know my mixtures will run very rich. I have an FCon which im hoping can trim up the fuelling for me, else will i have to get a FPR?

Cheers guys.
Click to expand...


If you replace just the pump, you're mixture will not be rich. Many have replaced just the pump w/ everything else the same and reported no problems.
 
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illGT4

New member
enzytebob":3d7817um said:
-==L=a=N=c=E==-":3d7817um said:
While the tank is out ive decided to get a 2nd hand SupraTT pump. They are a direct bolt in as far as im told.

Now after the upgrade, i know my mixtures will run very rich. I have an FCon which im hoping can trim up the fuelling for me, else will i have to get a FPR?

Cheers guys.
Click to expand...


If you replace just the pump, you're mixture will not be rich. Many have replaced just the pump w/ everything else the same and reported no problems.
Click to expand...

The pump flows a lot more than the OEM pump. . BUT if you have a good FPR it shouldn't change the feuling.. :shrug:
 
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illGT4

New member
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tweekgt4

Member
haven't dyno tutned the car but i'm still rich doing about 16-18 psi. still below 75 psi. then again, i think my pump can go up to 90 psi. i don't plan on ver boosting that much more anyways.

illGT4":9wz4qm3s said:
tweekgt4":9wz4qm3s said:
if you modify the stock rail to be a dual feed, you don't have to worry about the pressure drop.

i have also heard that the stock fuel pressure regulator is not very consistent so it should be on the list of things to change out when doing a fuel upgrade.

my current setup now is a supra tt fuel pump, stock dual feed fuel rail, SX rising rate fpr, and st205 540cc injectors at a base pressure of 50 psi.
Click to expand...

What boost pressure are you running? Rather what have you got it tuned to?
Click to expand...
 
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